fix: add support for leading tab characters with trim-kotlin-indent.

[testersen]

We're using Springdoc with Kotlin + Ktlint. We have configured Ktlint to use tabs instead of spaces as indents.

	@GetMapping("/assets")
	@Operation(
		operationId = "getAssets",
		summary = "Get the assets of the signed in user",
		description = """
			Get the assets owned by the currently signed in user.
		""",
		// ^^^^ Tab characters here turned into a code block.
	)
	@[WithExternalEndUser ScopesAllowed("...")]
	fun getAssets(
		@RequestParam(required = false, defaultValue = "nb-NO") locale: String,
	): List<AssetCard> = TODO()

This pull request appends on the condition in the countLeadingSpaces method where the count loop filters on spaces. The change makes the condition break on a non space or tab character.

[testersen]

@bnasslahsen Heyo :) Any ETA for when we can look into merging this? Would you like to see any changes in this suggestion?